The present invention relates to power diodes and, more specifically, to a power diode and heat sink arrangement, which improves the performance of heat dissipation and, protects the chips against deformation and displacement during its installation.
FIG. 1 shows the arrangement of a power diode and heat sink for use in an electronic apparatus of high power output. This structure of power diode and heat sink arrangement comprises a heat sink 1xe2x80x2, and two power diodes 2xe2x80x2 installed in the heat sink 1xe2x80x2. The power diodes 2xe2x80x2 each comprises two chips 21xe2x80x2 respectively soldered to the heat sink 1xe2x80x2 each chip 21xe2x80x2 having two molybdenum pads 23xe2x80x2 respectively soldered to top and bottom sides thereof, a copper plate 22xe2x80x2 connected between the chips 21xe2x80x2 at the top side and soldered to the top-sided molybdenum pads 23xe2x80x2 of the chips 21xe2x80x2, a terminal holder 24xe2x80x2 fastened to the copper plate 22xe2x80x2 at the top side, and a copper screw 25xe2x80x2 fastened to the terminal holder 24xe2x80x2 to secure an electric wire. Because the copper plate 22xe2x80x2 is suspended above the heat sink 1xe2x80x2, the forward stress and side torsional force are directly transmitted to the copper plate 24xe2x80x2 and the chips 21xe2x80x2 when fastening up the copper screw 25xe2x80x2, thereby causing the copper plate 22xe2x80x2 to deform and the chips 21xe2x80x2 to displace easily.
The present invention has been accomplished to provide a power diode and heat sink arrangement, which eliminates the aforesaid problems. It is one object of the present invention to provide a power diode and heat sink arrangement, which achieves a high performance in heat dissipation. It is another object of the present invention to provide a power diode and heat sink arrangement, which protects the copper plate and the chips against deformation and displacement. According to the present invention, a ceramic pad is connected between the heat sink and the copper plate of each power diode and spaced between the chips of the respective power diode and adapted to support the copper plate against deformation and to transmit heat from the copper plate to the heat sink for quick dissipation.